| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the influence of the variation of a disturbance magnetic field, the temperature drift of a sensor, and the acceleration and the deceleration of a vehicle when a magnetic marker body on a travelling road is detected so as to obtain the position of the vehicle. SOLUTION: A vehicle detects magnetic marker bodies intermittently disposed on a travelling road by a horizontal magnetic sensor 5a and a vertical magnetic sensor 5b so as to travel along the magnetic marker bodies. The signals of the horizontal and the vertical magnetic sensors 5a, 5b are input to an position computing device 7 via the horizontal and the vertical sensor amplifiers 6a, 6b. The signal of the vertical magnetic sensor 5b is input to a peak and bottom discrimination device 8 so as to discriminate the signal peak of the vertical magnetic sensor 5b. The one half time position of required time between two past peaks is set as a zero point by the detection circuit 7a of the position computing device 7, and the zero point is corrected based on the change of a passing time between the past peaks resulting from acceleration and deceleration by a correction circuit 7b. The reference voltage level of the horizontal and the vertical magnetic sensor 5a, 5b are adjusted at the correction zero point. |
